Pour 1 cup of boiling water into the jello crystals and stir until they are well mixed.
Then add 1/2 cup vodka, 1/4 cup Limoncello, the juice of one lemon (about 3 Tablespoons) and enough cold water (about 1 Tablespoon) to bring the total cold liquids amount to 1 cup.
Stir again.
Fill the shot cups about ¾ full with the jello mixture
Refrigerate for 2 to 4 hours until set.
Notes
Spreading the shot cups out on a cookie sheet makes them easy to transport to the refrigerator and helps to catch spills.
Using shot cups with lids makes them stack-able which saves on refrigerator space.
You can vary the amount of vodka, Limoncello, lemon juice and cold water you add depending on how strong and how lemon-y you want the flavor to be. You can even eliminate the water for stronger jello shots.
Just make sure that the total amount of cold liquids comes out to no more than 1 cup. Otherwise, the jello may not set.
Adding all of the cold liquids to a measuring cup before pouring them into the jello mixture helps to make sure you have the right amount
Letting the jello mixture cool in the shot cups before putting the lids on will prevent condensation from forming on the inside of the lids.
These jello shots can be stored in the refrigerator for up to 2 days before they start to lose their flavor.